The 2013 Nissan Altima, introduced at the New York auto show, is being pitched into a mid-size family-sedan market that has never had as many new, competitive models.

2013 Nissan Altima Sedan

2013 Nissan Altima Sedan

2013 Nissan Altima Sedan

2013 Nissan Altima Sedan

2013 Nissan Altima Sedan

2013 Nissan Altima Sedan

2013 Nissan Altima Sedan

By the end of 2012, all of the traditional big sellers in the segment (Honda Accord, Toyota Camry, Chevrolet Malibu, and Ford Fusion) will be either new-for-2013 or freshly launched in the last year or two. And that list doesn’t even include the vehicles that are newly relevant in the market, such as the Hyundai Sonata, Kia Optima, and Volkswagen Passat. And, for good measure, a new Mazda 6 will be on sale early next year.

Nissan, which is proud to point out that its 2012 Altima outsold everything but the Camry last year, will enter the market with an all-new car that sticks to the basic parameters of its proven formula.

The new car rides on the same 109.3-inch wheelbase and grows only about an inch in overall length. It’s 1.3 inches wider than the outgoing car. It rides on a strut front and multilink rear suspension (although Nissan notes that the rear setup has been redesigned to improve handling prowess). It is powered, as it has been for years, by either a 2.5-liter inline-four or a 3.5-liter V-6, but now will be offered—at least at launch—only with a CVT automatic. (We had previously believed a manual would be available with either engine; this is looking unlikely for now or the future.)

But that 2.5-liter gets a 7-hp bump to an estimated 182, while dropping 11 pounds of mass. A substantially reworked CVT (70 percent of its parts are new for a 40-percent reduction in internal friction) helps deliver an estimated 15-percent improvement in fuel economy when mated to the four-cylinder. It helps improve fuel economy by 10 percent when mated with the carry-over 270-hp V-6. The end result, estimates Nissan, is class-leading fuel efficiency of 27 mpg city and 38 mpg highway. That’s higher than Chevrolet’s light-hybrid Malibu Eco. The V-6 models are estimated to return 22/30 mpg, city/highway.

Overall, the Altima sedan has dropped 79 pounds of curb weight, according to the company, which would make it one of the lightest in the class. The car certainly doesn’t look light, though. Its increased width and curvaceous, almost chunky, body makes it appear substantial. The new look mixes stylistic elements from throughout the Nissan family: a little Infiniti G37 in its surfacing, some Maxima in its headlights and undulating flank, and, from the Ellure concept sedan shown at the 2010 Los Angeles auto show comes a big, chrome-framed grille.

The body is stiffer thanks to greater use of high-strength steel, a new front strut-tower brace and additional structural support aft of the passenger cabin. And the body has a claimed five-percent-lower coefficient of drag. The smoother shape and increased sound-deadening material have quieted the newly designed cabin. Predictably, Nissan says the cabin is nicer than in previous versions of the car. It features a bevy of standard and optional electronics; this includes a four-inch, reconfigurable color display between the analog gauges that can display audio system settings, instant MPG, trip-computer readouts, and turn-by-turn navigation directions. And in a moment of real cuteness, the pictogram of the car displayed on the screen can be matched to the actual color of the individual car.

The Altima will be offered with a bevy of so-called driver aids (which we reckon should probably be thought of as people-who-shouldn’t-really-be-drivers aids) including blind-spot warning, lane-departure warning, and something called moving-object detection. The last two of those use a rear-mounted camera to either watch lane markers for the lane-departure system or, well, detect moving objects behind the car and warn the driver while backing up.

Not enough electronics for you? The Altima also offers Active Understeer Control, which grabs the inside front brake to point the nose to the inside of the corner before the car noticeably understeers. So think of it as a first, allegedly undetectable, line of defense before the standard stability-control system is needed.

The seats, says Nissan, are “NASA-inspired ‘zero-gravity’” units, which we take to mean that you should restrain yourself with a seatbelt at all times.

The new sedan will be built in Smyrna, Tennessee, and Canton, Mississippi, and available in base-level, S, SV, and SL trims with the 2.5-liter, and S, SV, and SL versions with the V-6.

Nissan will continue to produce the currently available Altima coupe through the 2013 model year. Eventually, the company will introduce a two-door version of this new car. A second-gen hybrid version—this time using Nissan’s own technology—also is in the works.